Week 5: Dermatology 2 (common skin conditions) Flashcards
Emergency dermatology
- Urticaria, angioedema and anaphylaxis
- Erythema nodosum
- Erythema multiforme
- Steven Johnson
- Necrotizing fasciitis
Skin infections
- Cellulitis
- Impetigo
- Fungal infections
- Folliculitis
- Pityriasis rosea
- Scabies
Skin cancer
- Basal cell carcinoma
- Squamous cell carcinoma
- Malignant melanoma
Inflammatory skin conditions
- Atopic eczema
- Acne vulgaris
- Psoriasis and different types
Erythema nodosum
- A type of panniculitis, an inflammatory disorder affecting subcutaneous fat
causes of Erythema nodosum
- Hypersensitise reaction of unknown cause in most patients
- In other case:
- Inflammatory condition
- IBD
- Sarcoidosis
- TB
- Drug
- Amoxicillin
- Oral contraceptive
- Infection
- Streptococcal
- malignancy
- Inflammatory condition
more common in women
presentation of erythema nodosum
- Bilateral tender erythematous nodules on the anterior shins (less commonly, thighs and forearms (rarely on face))
- 3-20cm
- Accompanied by fever and joint pain – swollen ankle most common
management of erythema nodosum
- Treatment of underlying condition e.g. crohns, sarcoidosis, tuberculosis, throat infection
- Anti-inflammatory drugs e.g. ibuprofen and cortisone
- They spontaneously resolve within 8 weeks
Erythema multiforme (major and minor)
- Hypersensitivity reaction usually triggered by infections, most commonly herpes simpelx virus (HSV)
- Divided into major and minor forms
causes of erythema multiform
- Usually young adults
- Genetic tendancy
- Triggers
- Drugs
- barbiturates
- NSAIDS
- penicillin
- Infections
- mycoplasma pneumonia
- Herpes varicella-zoster
- Dermatophyte fungal infections
- Drugs
presentation of erythema multiforme
- Eruption characterised by target lesion (few to hundreds within 24 hours)
- First seen on the back of hands/ top of feet and then spread down limb towards trunk
- Mucous membranes may be involved
- May have fever or chills and arthralgia
management of erythema multiforme
- Treatment of underlying condition
- Acute and self limiting, usually resolving without complications
- Itching- antihistamine/corticosteroids topical
- Eye involvement should be treated by ophthalmologist
- Recurrent erythema multiforme usually treated with oral acyclovir for 6 months
- Skin biopsy may need to done to exclude other conditions
Urticaria, angioedema and anaphylaxis
-
Background (also known as hives, weals, or nettle rash) is a superficial swelling of the skin (epidermis and mucous membranes) that results in a red (initially with a pale centre), raised, and intensely itchy rash.
- Angio-oedema is a deeper form of urticaria with transient swellings of deeper dermal, subcutaneous, and submucosal tissues, often affecting the face (lips, tongue, and eyelids), genitalia, hands, or feet. For more information, see the CKS topic on Angio-oedema and anaphylaxis
- Urticaria and angio-oedema can co-exist (in about 40% of cases), but either can occur separately
- Consider vasculitic urticaria – if lesion remain for longer 24hs and are painful, non blanching and palpable (esp in conjunction with fever, malaise and arthralgia)
Causes/ risk factors of urticaria, angioedema and anaphylaxis
Mast cell driven disease → release histamine, leukotrienes and prostaglandins. Triggers include
- Certain foods
- Certain plants, animals, latex
- Cold
- Hot, sweaty skin e.g. emotional stress
- Insect bite
presentation of urticaria and angioedema
- Pruritus
- Vascular permeability
- Oedema
- Rash: erythematous swelling of various shapes and sizes, classically have central pallor with erythematous flare
management of urticaria
- Investigations not usually required unless indicated in history and exam
- Identify underlying cause e.g. trigger factor/ new drug
- Antihistamine e.g. cetirizine
- If symptoms severe give prednisolone for up to 7 days
- If inadequate response increase dose of antihistamines
Necrotising fasciitis
is a very serious bacterial infection of the soft tissue and fascia. The bacteria multiply and release toxins and enzymes that result in thrombosis in the blood vessels. The result is the destruction of the soft tissues and fascia.
3 main types
three types of NF
Type I- polymicrobial
Type II- due to hameolytic group A streptococcus and/or staphylococci MRSA
Type III (gas gangrene e.g. due to clostridium)
causes/risk factors of encrotizing fascitis
- Most cases are of streptococcal necrotising fasciitis in young individuals
- Opening in the skin e.g.
- Mandibular fracture and dental infection
- Direct contact with someone else with it
- Risk factors
- NSAIDs
- Older
- DM
- immune suppression
- obesity
- drug abuse
presentation of NF
- Early symptoms can include:
- a small but painful cut or scratch on the skin
- intense pain that’s out of proportion to any damage to the skin
- a high temperature (fever) and other flu-like symptoms
- After a few hours to days, you may develop:
- swelling and redness in the painful area – the swelling will usually feel firm to the touch
- diarrhoea and vomiting
- After a few hours to days, you may develop:
dark blotches on the skin that turn into fluid-filled blisters
investigations for NF
plain X-ray or CT scan may show soft tissue gas
management of NF
- Surgery to remove infected tissue (amputation may be required)
- Antibiotics
- Vancomycin IV plus clindamycin
- Supportive treatment e.g. IV fluids
Pathophysiology of NF
The infection starts in the superficial fascia. Enzymes and proteins released by the responsible micro-organisms cause necrosis of fascial layers. Horizontal spread of infection may not be clinically apparent on the skin surface and hence diagnosis may be delayed. The infection then spreads vertically up into the skin and down into deeper structures. Thrombosis occludes the arteries and veins leading to ischaemia and necrosis of the tissues.
Steven Johnson syndrome background
- Immune-complex-mediated hypersensitivity disorder.
- Ranges from mild skin and mucous membrane lesions to a severe, sometimes fatal systemic illness:
- toxic epidermal necrolysis (TEN).
- SJS, SJS/TEN overlap and TEN form a spectrum of severe cutaneous adverse reactions (SCAR) that can be differentiated by the degree of skin and mucous membrane involvement.
RF for steven johnson sndrome
female, HIV and 10-30yo, gentic changes related to HLA
SJS usually caused by
drugs… but can also be causes by ifnections
drugs which cause SJS
- Allopurinol
- Carbamazepine
- Trimethoprim
- Abacavir
- Phenytoin, lamotrigine
- Sertraline
- NSAID
infections which cause SJS
- Viral: HSV, Epstein- barr virus, enteroviruses, HIV
- Bacteria: Group A beta-haemolytic streptococcus, diphtheria, brucellosis, mycobacteria, Mycoplasma pneumoniae
- Protozoal: malaria and trichomoniasis
presentation of SJS
- Nonspecific URTI, fever, sore throat, chills, headache, muscle ache, V and D
- Mucocutaneous lesions develop suddenly and clusters of outbreaks last from 2-4 weeks
- Severe mucosal ulceration
- Pt with genitourinary involvement complain of dysuria
-
Signs
- Tachycardia, hypotension, fever, seizure, coma
-
Skin
- Lesions occur mainly on palms, soles, forsum of hands, extensor surfaces, trunk
- Macules papules vesicles blue urticarial plaques
- Centre of the lesion may. Be vesicular, purpuric or necrotic
- Target
- Lesions become bullous and rupture
- Not pruritic
- Nikolsky sign positive
- Corneal ulceration
investigations for SJS
-
Investigations
- Skin biopsy will demonstrate bullae are subepidermal
management of SJS
- Remove causative drug
- Intensive care may be required
- Supportive e.g. IV fluid, pain control, lesions treated as burns
- Topical anaesthetics, eye care
- Treat secondary infection
- Immunomodulation e.g. corticosteroids, DMARDS e.g. ciclosprin, anti-TNF monoclonal
folliculitis
- Folliculitis means an inflammation or infection of the hair follicles of the skin.
- Due to obstruction in pilosebaceous glands +- infection
cause sof folliculit s
- Infection e.g. S.aureus, fungal e.g. Candida spp, herpetic folliculitis (HSV)
- Immune system e.g. eosinophilic folliculitis
- Physical irritation
- Risk factors
- Uncut beard
- Shaving ‘against the grain’
- Thick hair
- Excessive sweating
- Skin abrasion
resentation of folliculitis
- It may occur as a relatively trivial irritation - superficial folliculitis, or as a more deep-seated process involving the lower hair follicle
- Symptoms
- Rash
- Scratch
- Pustule
- Erythema if deep folliculitis
- Regional draining of lymph nodes should be checked for adenitis mild folliculitis
- Folliculitis of eyelast- stye
management of folliculitits
- Avoid precipitating factors
- Use moisturizing shaving products
- Shave with the grain
- Good skin hygiene
- Superficial – antiseptics
- Deeper- oral antibiotics e.g. flucloxacillin, erythromycin
- May need surgery
cellulitis
- Acute, painful and potentially serious infection of the skin and subcutaneous tissues.
- Infection of the dermis and subcut tissue
causes of cellulitis
- Streptococcus or staphylococcus ( aureus) species or rarely fungal
RF for cellulitis
- Previous cellulitis
- Venous insuff
- Elder
- Alcohol dependency
- IV drug use
- Insect bites
- Obesity
presentation of cellulitis
- Poorly demarcated borders
- Lower limb unilaterally
- Sometimes precipitating skin lesion
- Blisters and bullae
- Systemic symptoms e.g. fever and mails
- Red line streaking represents progression of infection to lymphatic system
- Crepitus
investigations for cellulitis
- Clinical – raised CRP, fine needle aspiration to assit diagnosis, culture fluids
management of cellulitis
- Fluclox
- Rest and elevate
- NSAIDS
- Clean wound (debride)
- Emollient
Pityriasis rosea background
acute, self-limiting rash which tends to affect young adults.
causes of pityriasis rosea
- The aetiology is not fully understood but is thought that herpes hominis virus 7 (HHV-7) may play a role.
Presentation of pityriasis rosea
- minority may give a history of a recent viral infection
- herald patch (usually on trunk)
- a ‘fir-tree’ appearance
management of of pityriasis rosea
self-limiting- disappears in 6-12 weeks
differentiating guttate psoriasis and pityriasis rosea
impetigo
superficial bacterial skin infection- very contagious
causes of impetigo
- Staphylococcus aureus or streptococcus pyogenes
- Can be primary or complication of eczema, scabies or insect bites
- Common in children
- Spread by direct contact
presentation of impetigo
- Can be anywhere but especially found on the face, flexures and limbs
- ‘golden’ crusted skin lesions typically found around mouth
- Very contagious
management of impetigo
- For those not systemically unwell- hydrogen peroxide 1% cream
- Topical fusidic acid or mupirocin
- Extensive disease- oral flucloxacillin or erythromycin if pen allergic
- Should be excluded from school
Dermatophytosis (tinea) infections
- Infections caused by dermatophytes
- Invade and grow in dead keratin
- Produce ring-like patter
- Very common and affect diff parts of the body
tinea infections according to site
causes of tinea infecitons
Cause
- Infections transmitted from person to person, from soil or animals
- Most common organisms
- Trichophytons rubrum
- Trichophytons tonsurans
presentation of tinea infections
- Itching, rash and nail discolouration are the most common symptoms of tinea infection.
- Hair loss occurs with tinea capitis (mainly a disease of children).
- Complications such as secondary infection (cellulitis and impetigo) can lead to symptoms.
- It is common in people who play contact sports.
- It occurs in immunocompromised patients.
tinea pedis
- Athletes foot
- Plantar surface- erythema, vesicles, pustules
- Medication: miconazole (Daktarin)- oral
tinea capitis
hair loss- can be scaly, crusting
management of tinea infections
- Hygiene measure
- Antifungals
ring worm managament
clostrimazole ‘ tinea corporis’
Scabies
is an itchy rash caused by the parasitic mite Sarcoptes scabiei.
causes of scabies
- Spread through prolonged skin contact
- Typically affects children and young adults
- The scabies mite burrows into the skin, laying its eggs in the stratum corneum. The intense pruritus associated with scabies is due to a delayed-type IV hypersensitivity reaction to mites/eggs which occurs about 30 days after the initial infection.
RF for scabies
- Overcrowding
- Poverty
- Poor nutritional status
- Poor hygiene
- Sexual contact
- Immune suppression e.g HIV
- Most common in children
presentation of scabies
- Severe pruritus worse at night
- Close contact with people with similar symptoms
- White lines → indicative of mite burrowing
- Lesion may be
- Papules
- Vesicles
- Pustules
- Nodules
- erythematous
management of scabies
(everyone in household treated)
- permethrin 5% is first-line
- malathion 0.5% is second-line
- pruritus persists for up to 4-6 weeks post eradication
best -→ worse skin cancers
BBC→ SCC →Melanoma
basal cell carcinoma
- Most common skin cancer
- Slow growing, locally invasive arise from hair follicle
- Subtypes include nodular, morphoeic, superficial and pigmented
- Slow growing with low metastatic potential
RF of BCC
- Caucasiann (type I and II)
- Sun exposure (UV)
- Immunosuppression
- Albinism
presentation of BCC
- Occurs in sun exposed sites apart from the ear
- Early lesions are small, translucent or pearly and have raised areas with telangiectasia
- Indurated edge and ulcerated centre
- Slow growing but can spread deeply to cause considerable destruction
diagnosis of BCC
- Visual inspection
- Punch biopsy if treatment other than standard surgical excision is planned
anagement of BCC
- Can be managed in primary care as long as GP trained to perform skin surgery
- Surgical excision
- Mohs micrographic surgery
- Non-surgical
- Curettage and cautery
- Imiquimod cream
- Radiotherapy
squamous cell carcinoma
- Malignant tumour arising from keratinising cells of the epidermis
- Locally invasive and has the potential to metastasise
RF for SCC
- Related to sun exposure (UVR)
- Fair skin
- Chemical carcinogens- arsenic
- HPV
- Chronic inflammation
- May arise in pre-existing solar keratoses
- Immunosuppression after transplant
presentation of SCC
- Indurated nodular keratinising or crusted tumour that may ulcerate without evidence of keratinisation
- Non healing ulcer or growth in one of the highest risk sun exposed area
- Centre becomes necrotic and becomes an ulcer
- Ulcer with hard, raised edges
- Slow growing
- Bleeding
diagnosis of SCC
visual inspection
removal for histology
management of SCC
- Wide local excision – repeat surgery to gain adequate margins may eb required
- Mohs’ micrographic surgery- precise technique in which excision of skin lesion is carried out in stages and checked histologically
- Othe non-surgical procedures
- Curettage and cautery
- Crytotherapy
- Imiquimod cream
- Photodynamic therapy (PDT)
- Electrochemotherapy
- Radiotherapy
melanocytes
- Melanocytes are found in equal numbers in black and in white skin; however, the melanocytes in black skin produce much more melanin. People with dark brown or black skin are very much less likely to be damaged by ultraviolet (UV) radiation than those with white skin.
non-cancerous growths of melanocytes
- results in moles (benign melanocytic naevi) and freckles (ephelides and lentigines).
most skin melanomas spread out within the epidermis…
If all the melanoma cells are confined to the epidermis then the lesion is a melanoma in situ, which can be cured by excision because it has no potential to spread around the body
When the melanocytes have grown through the dermis it is known as
invasive melanoma → malignant melanoma
RF for melanoma
- Previous primary invasive melanoma
- Naevi – moles
- Sun exposure
- Family history
presentation of malignant melanoma
- Common sites for metastases are lymph nodes, liver, lung, bone and brain. In-transit metastases are deposits from a focus of cells moving along regional lymphatic channels
- Asymmetry.
- Border irregular.
- Colour irregular.
- Diameter greater than 7 mm.
- Evolving.
- ABCDE
diagnosis of melanoma
- Visual inspection
- Removal for histology
- Staging (TNM)
management of melanoma
- Wide local excision (look for margins)
- Vitamin D should be optimal
- Palliative care treatment
- Immunotherapy- ipilimumab
- Cytotoxic chemo- dacarbazine
*
atopic eczema
- a chronic, relapsing, inflammatory skin condition characterised by an itchy red rash that favours the skin creases such as the folds of the elbows or behind the knees
- can become infected crusting, weeping e.g. cellulitis
causes of atopic eczema
- Environmental irritant and allergens
- Soaps and detergents
- Skin infections- SA
- Contact allergens
- Dietary factors e.g. egg
- Inhaled allergens e.g. dust mites
- Genetic mutations
- Stress
- Hormonal changes
Diagnosis of atopic eczema
- Diagnostic
- Itchy skin condition +
- Itchiness in skin flexor regions
- History of asthma or hay fever
- General dry skin
- Itchy skin condition +
atopic eczema management
- Education
- Provoking factors avoided
- Emollients form basis pf treatment (3-4 times a day)
- Corticosteroids
- Mild :For face and flexure (hydrocortisone)
- Potent corticosteroid required for adults with discoid or lichenified eczema ( watch out for topical corticosteroid withdrawal)- bectamethasone
Acne vulgaris
- Acne vulgaris is a disorder of the pilosebaceous follicles found in the face and upper trunk. At puberty androgens increase the production of sebum from enlarged sebaceous glands that become blocked
- Closed comedone- whiteheads
- Open comedones- blackheads
- Inflammation leads to papules, pustules and nodules
RF for acne vulgaris
- Adolescence
- PCOS
- Greasy substances used
- Fx
management of acne vulgaris
- Avoid over cleaning the skin
- Avoid oil based comedogenic skin care products
- Wash makeup off
- Do not pick of scratch
- 12 week course of:
- Topical adapalene with topicals benzoyl peroxide
- Or topical tretinoin with topical clindamycin or doxycycline
- COCP should be considered
- Oral roaccutane (tretinoin)
psoriasis
- Psoriasis is a long-term skin condition that can also affect the nails and joints. It tends to flare up from time to time. (psoriatic arthritis- pitting, oncyholys = nail signs))
- Increases risk of arthritis and CVD- inflammation of vasc
- Subtypes
plaque psoriasis
: the most common sub-type resulting in the typical well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp
flexural psoriasis
- : in contrast to plaque psoriasis the skin is smooth
guttate psoriasis
- transient psoriatic rash frequently triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body trunk
pustular psoriaiss
commonly occurs on palms and soles
pathophysiology of psoriasis
- Occurs due to increased production of skin cells
- Skin cells normally replaced every 3-4 weeks, however in this chronic condition it only takes 3-7 days
- Underlying cause not fully understood- to do with immune system mistaking healthy cells
triggers of psoriasis
- Injury to skin
- Throat infection- step
- Medications
- Stress
- Infection
- Smoking andf alcohol
presentation of psoriasis
Erythromatous, crusty skin covered with silvery scales
management of psoriasis
- Emollient
- Corticosteroids
- Vitamin D analogues
- Salicylic acid (helping ointment peneatrate skin)
- Tar preparations
- Second line
- Phototherapy (UV B)
- DMARDs e.g. TNF antagonist adalimumab
fir tree- pityriasis rosea
